Due to progress in photoelectric technology, digital audio and video technology can be used to acquire a high quality image and sound effects. Therefore, DVD (digital versatile disk) drives are nowadays widely used. Currently, when defect in the compact disk is detected, the data slicer in the DVD drive is still in the normal gain. As a result, when the defect comes to an end, the data slicer can not chase to a correct slicing level so that the time period of data fault can not be reduced effectively. Therefore, the above mentioned technology is highly needed to be improved.
For the data slicer technology, one of the prior art is illustrated in FIG. 1. In FIG. 1, a comparator 40 compares the signals XI4 with VC4, and outputs a signal XC4. Then the comparator is connected to a digital sum value (DSV) calculator 42 for further processing and then a DSV signal is outputted. The DSV signal is then sent to a DSV processor 44 for data slicing.
The DSV processor 44 includes a filtering unit 45 for filtering the DSV signal. The DSV processor 44 generates a digital correcting signal, which is sent to a digital/analog converter 48 for being converted into an analog signal VC4. The VC4 is used to adjust the reference slicing level of the data slicer. Then it is connected to an input of the comparator. As a result, a digital data slicer is accomplished.
Different from the prior art, in the present invention, an analog data slicer is disclosed. Through the adjustment of gains, the time period of data fault is reduced after a defect occurs.